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Peter:
It was clear from your posting, that good
airflow in a container will help to slow down the rate of acetic acid
build-up, thus helping to slow down the rate of deterioration. My concern
with your posting, is when you mentioned that "cardboard boxes would work well".
It needs to be added that the "old" cardboard boxes are usually not inert to
begin with, and have a very high Ph, they will decompose over time and
eventually give off acid on their own. Certainely, we have all seen old acetate
tapes that have turned brown, sometimes even leaving an imprint of the plastic
reel. Since this is true, then the acid that is emitted from the breakdown
of the cardboard boxes will actually help to speed up the deterioration,
unless new inert boxes are utilized.
Thanks,
Lance Watsky
Preservation
& Media Specialist
The Georgia Archives
5800 Jonesboro Road
Morrow,
GA 30260
678-364-3764 (phone)
678-364-3860 (fax)
lwatsky@xxxxxxxxxxxxxxx
www.GeorgiaArchives.org
From the testing I've
reviewed, it's pretty clear that acetic acid will catalyze the breakdown of
acetate. As such, any method (that does not otherwise damage the
acetate) of removing traces of the acid from proximity to the tape
should help slow down the reaction. Testing has shown that acetate
tapes will decay slower if they are exposed to an air-flow that removes the
residual acid than will tapes that are in sealed containers that trap the acid
inside. Cardboard boxes would work well for the simple reason that
they are not air-tight and allow the acid to escape.
It's also important to
have a positive air pressure and air flow in the storage area so that the acid
is removed from the area. Removing the acid from the proximity of one
tape and then trapping it in a room can catalyze breakdown in other tapes
stored in the same space.
The Tuscan cans should
work ok as long as there is enough air movement in the room to allow some air
to circulate through the air vents and channels in the
cases.
Peter Brothers
In a message dated 8/9/2004 5:11:12 PM Eastern Standard Time,
ArcLists@xxxxxxxxxxxxxxx writes:
I'm suspicious
that the traditional cardboard box is
functioning something like a
molecular sieve and absorbing some of the
acetic acid outgassing/effluent
from the tapes and retarding any
vinegar syndrome.
***************
Keeping tape in unsealed cardboard boxes does seem to
help preserve it.
"ProVent Audio's vented design allows active airflow through the
container to prolong the life of audio tape or 8mm film."
Everything I've seen indicates that you want to get the acetic acid out
of the room completely, not trap it near the acetate. Controlling the
room's humidity should prevent excessive drying.
The thickness of film base may be a factor in preventing the acetic
acid from leaving the material, explaining the faster deterioration, however
the compulsion to seal film in metal cans in sealed vaults
certainly has a greater effect. I've yet to see vinegar syndrome in any
of my 40+ year old tape or film, however the material I just
received from a friend who was meticulous about "protecting" his material
definitely does show the effect (now stored in a separate room for
airing).
Mike Csontos
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